This chapter looks at the relationship between economic development and cities, exploring the many different ways that flows of capital and networks of exchange of knowledge and goods reshape urban processes. The links between global economic centres represent a geographical reorganisation of capitalism, where the traditional geographic centres no longer operate as individual sites of capital and production. Urban economies are therefore reconfiguring spatial relations between cities, facilitated by high-speed communication networks, creating a pattern of hyperconnected global financial hubs. In the last 30 years, the growth in internet capacity and the rise of the 'network society' has meant that the intensity, complexity, and global span of these networks has heightened connectivity between cities. As part of the growth of the knowledge economy, cities increasingly use the term to define themselves within a global context. Global cities are now shaped by their linkages into diverse ranges of economic and spatial networks.